It was after they took her finger that Layla decided to leave. 

She snuck out of the compound when the others, exhausted from celebrating the ritual, had all fallen asleep. The pain in her left hand was agonizing. Her mind kept replaying the moment. Her hand being strapped down. The jagged blade of the knife. Seeing a stump gushing blood where her middle finger had been. Screaming. She had been the only one screaming. 

Give yourself to me. You are broken and I can fix you. A substitute can be arranged.

The horrifying words haunted her. They had given her the push to finally flee.